Types of legal barriers to market entry exist: Kinds of legal barriers which make that difficult for the newer drug in the generic form towards entering market have been lack of the rigorous assessment about the patentability needs; thirty mouth stay has been 1 way for preventing the other drugs to get on market towards competing with its drug. The thirty month stay has been if the company files the suit to the patent infringement among forty five days to receive the Paragraph 4 letter. Reason to stay has been permitting the
parties towards litigating a patent infringement claims whereas ANDA filer proceeds for the FDA approval of their generic drug. Citizen petition may be other barrier that means when the petition may request a Commissioner towards issuing, amending, as well as revoking the regulation, which have been exact words of present regulation as well as proposed regulation & amendment requested.
Also it may mean that the Commissioner must take & refrain to take any other form of the administrative actions. Other reason may be the cost benefit, Advertising as well as marketing, the research & the development expenditure, and also the sunk cost.